The new boutiques.

Byline: Joshua Jaffe in San Francisco

Investment bankers in San Francisco call it "the void." That's the vacuum created by the disappearance of the city's first generation of homegrown boutique investment banks and the retreat of New York's bulge-bracket securities firms and their global rivals from all but the commanding heights of the technology investment banking business.

A decade or more ago the legendary Four Horsemen -- Robertson Colman & Stephens (which later became San Francisco-based Robertson Stephens Inc.), Hambrecht & Quist, also of San Francisco, C.E. Unterberg, Towbin of New York and Baltimore-based Alex. Brown -- would have filled the void. But those four boutique banks and their closest rival, San Francisco's Montgomery Securities, were acquired or dismantled (or both, in succession) by larger East Coast or European interlopers as the tech bubble of the late-20th century picked up steam.

And in their place? Well, no one's in their place today, at least not yet, but a score or more small-to-medium-size investment banks are angling to become the latest Four Horsemen of Silicon Valley. "There's a void, that's obvious," says Richard Osgood, CEO of Pacific Growth Equities Inc., one of the new firms that counts itself among the rising generation of San Francisco boutique banks. "As for who's going to fill it, that isn't obvious."

Contenders include high-profile bankers such as Thomas Weisel, the founder of Montgomery who launched Thomas Weisel Partners LLC in 1999 after Montgomery's acquisition by Bank of America Corp. But the list also includes less familiar bankers, among them former Montgomery executive Ron Lissak, managing partner of 2-year-old Catapult Advisors LLC, an M&A and private placement boutique focused exclusively on the software industry.

Challenging Weisel's eponymous full-service investment bank at one end of the spectrum and Catapult Advisors at the other are boutique shops scattered across San Francisco and into Silicon Valley. Some of them are well known to the larger investment banking world, including William Hambrecht's WR Hambrecht + Co. or regional rivals with a foothold in California, such as New York-based Needham & Co. or William Blair & Co. of Chicago.

Others are recognizable only to tech banking cognoscenti, and even then perhaps not by many. They range from boutiques offering full-service banking, such as Joseph Jolsen's JMP Securities LLC and Osgood's Pacific Growth …